#update
sudo apt update​
sudo apt upgrade​

#Installation Dependencies
sudo apt install ca-certificates curl openssh-server postfix​

#get package
wget -c https://mirrors.tuna.tsinghua.edu.cn/gitlab-ce/ubuntu/pool/focal/main/g/gitlab-ce/gitlab-ce_14.2.0-ce.0_amd64.deb​

#install
chmod 755 gitlab-ce_14.2.0-ce.0_amd64.deb​
sudo dpkg -i gitlab-ce_14.2.0-ce.0_amd64.deb​